University:
Felician University
Course:
BIO-405 | Genetics
Academic year:

2022
Views:

316

Pages:

3
Author:

InterstellarInnovator

Evidence of Evolution Кеу Words evolution adaptation fossil law of superposition homologous structures analogous structures vestigial structure embryology Since its fiery beginning nearly 4.6 Ьillion years ago, Earth has changed. lts temperature, climate, and structural features have changed. The organisms living оп Earth have changed as well. The Ьiological term for the process Ьу which species of organisms change over time is evolution. Much scientific evidence supports the theory that evolution has occurred among Earth's organisms. Change in Species The history of life оп Earth has shown that as species evolve, they develop new traits and lose other traits. Organisms with traits that make them better suited to their environments are more likely to survive and reproduce. As you learned in Lesson 37, any trait that improves an organism's chance for survival and reproduction is called an adaptation. Scientists look at many kinds of data to try to piece together the evolutionary histories of organisms. These data соте from observing fossils, comparing form and structure, studying embryos, and examining genetic material. These data help scientists learn how and why adaptations arise, how new species develop, and why many species are now extinct. Fossil Evidence of Evolution Fossils are the remains or evidence of organisms that lived in the past. Much evidence about past life-forms comes from fossils. Fossils also provide clues about when different species lived оп Earth. For example, а fossil's location in а rock layer provides clues about how long ago an organism lived оп Earth. The law of superposition states that in undisturbed sedimentary rock layers, older rock layers lie beneath younger rock layers. This law helps scientists determine when certain organisms lived. ln that way, fossils help scientists sequence the evolution of life оп Earth. For example, scientists would conclude that the fossil shown in the illustration is older than rocks or fossils in shallower layers and younger than rocks or fossils in deeper layers. Layers younger than fossil Layer about same � age as fossil � : /;�·-:\(.}: :·i)}}·\